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    SubjectRe: [PATCH] 2.4: variable HZ
    Hiya...  Nice patch, must try it when I find a few minutes - I think I
    have a few apps that are limited by select/poll behaviour.

    I was looking at your jiffies_to_clock_t() macro, and I notice that it
    will screw up badly if the user chooses a HZ value that isn't a multiple
    of the normal value (e.g. 1000 is OK, 512 isn't).

    How about tweaking the macro a little? Instead of:
    x / (HZ/USER_HZ)
    you could use:
    (x/HZ*USER_HZ + x%HZ*USER_HZ/HZ)

    which minimises roundoff error and also won't overflow (at least, it
    won't overflow as long as HZ*USER_HZ doesn't overflow!).

    You could even use both versions of the macro, choosing between them at
    compile time depending on whether or not (HZ % USER_HZ == 0).

    What do you think?

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      Last update: 2005-03-22 13:30    [W:0.060 / U:1.824 seconds]
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